Semiconductor devices require many layers of wiring to interconnect devices such as field effect and bipolar transistors into integrated circuits. Two major factors limit the speed of advanced semiconductors. The first is the wiring density, which is a function of wire dimensions, and the second is capacitance, which is a function of the dielectric constant of the material in which the wires are embedded. Therefore, there is an ongoing need for semiconductor interconnection structures and processes that are dense and have low capacitance.